Hold-open latch assembly

ABSTRACT

A hold-open door latch assembly for lightweight doors with upper horizontal hinge lines in combination with a door hinge having a door hinge leaf with a radially straight flat shouldered portion extending from the hinge pintle axis and a semi-cylindrical hinge leaf portion to which the door is fastened. A spring-loaded lever arm latch assembly fastens on the rear surface of the door jamb over the hinge leaf mounted thereon. Rollers on the end of the lever arm bear against the hinge flat shouldered portion of the door hinge leaf to maintain the door in a substantially horizontal open position yet offer low resistance to the closing of the door as the rollers press against the curved portion of the hinge during its closing.

Murphy et a1.

[ HOLD-OPEN LATCH ASSEMBLY [75] Inventors: Dennis E. Murphy, Costa Mesta;

Larry David Smith, Westminster, both of Calif.

1 [73] Assignee: McDonnell Douglas Corporation,

Long Beach, Calif.

[22] Filed: June 7, 1974 [21] Appl. No.: 477,201

[52] US. Cl. 292/256; 16/142; 292/78 [51] Int. C1. E05C 19/02; E05D 1l/08 [58] Field of Search 292/256, 79, 77, 76, 78; 16/142, 145,146,147

[56] References Cited UNITED STATES PATENTS 498,551 5/1893 Howarth 2.023.616 12/1935 Riddell 2.388.021 10/1945 Thomas 2.389.056 11/1945 Jamison, Jr... 2,460,881 2/1949 Goserud 2,817,870 12/1957 Howell 16/147 3.124.830 3/1964 Gionet 16/146 3.153.259 10/1964 Brissette et al7 16/142 Gorton 16/145 Primary ExaminerRobert L. Wolfe Assistant E.\'aminer Victor N. Sakran Attorney, Agent, or Firm-Donald L. Royer; Walter J. Jason [5 7 ABSTRACT A hold-open door latch assembly for lightweight doors with upper horizontal hinge lines in combination with a door hinge having a door hinge leaf with a radially straight flat shouldered portion extending from the hinge pintle axis and a semi-cylindrical hinge leaf portion to which the door is fastened. A spring-loaded lever arm latch assembly fastens on the rear surface of the door jamb over the hinge leaf mounted thereon. Rollers on the end of the lever arm bear against the hinge flat shouldered portion of the door hinge leaf to maintain the door in a substantially horizontal open position yet offer low resistance to the closing of the door as the rollers press against the curved portion of the hinge during its closing.

8 Claims, 5 Drawing Figures US. Patent N0v11,1975 Sheet10f2 3,918,755

Sheet 2 0f 2 3,918,755

US. Patent Nov. 11, 1975 1 BACKGROUND or THE PRESENT INVENTION A latch is needed to hold an aircraft baggage compartment door open yet permit its closing upon application of a small force. The door is hinged along its upper horizontal edge to permit the doorto swing from its closed position in asomewhat vertical plane to its open position in a. somewhat horizontal plane-More specifically, a 2% pound stowage compartment door in the passenger area must be held open in a horizontal position withoutobjectionable visible means of support, such as struts, and continue to hold it open through normal aircraft flight dynamic loads. The latch must be adjustable to permit alignment of a multiple of adjacent compartment doors in their open position.

There are hinge and latch combinations that maintain doors in open and in closed positions. Most of them operate along vertical hinge lines and thus do not support thedoor cantilevered from the hingein a horizontal position. Latch components are usually mounted on both the door and the door jamb and often are an integral part of the hinge. Usually the latches consist of spring-urged rollers engaging detents on cam surfaces to releasably retain the door in the desired open or closed position.

SUMMARY OF THE PRESENT INVENTION In accordance with the present invention a door hinge structure is'provided with a detent latch assembly means to latch the door in the open position. The swinging hinge leaf secured to the door is provided with a semi-cylindrical surface formed about the hinge pintle axis and terminates in a radially straight shoulder portion coupled to the hinge pintle. The anchor hinge leaf on the compartment or door jamb carries a springloaded arm link assembly arranged so that a roller provided on the end of the lever arm is positioned on the cylindrical surface of the swinging hinge leaf. As the door is opened, the roller moves over the cylindrical surface until the door opens sufficiently to present the flat shouldered portion of the hinge to the roller, whereupon the spring tension swings the roller in to abut the shoulder portion to maintain the door in that position.

The latch assembly is a modular entity which may be mounted on the door jamb only. This assembly may be mounted after the door is installed and uses the geometric shape of the door hinge structure in its operation. It applies pressure on the hinge at all times which provides an anti-rattle advantage. The latch assembly has a position adjustment capability for door hold-open position alignment with adjacent doors. The'use of a compression spring instead of the inherent resilience of a torsion or leaf spring improves the reliability and function of the assembly.

BRIEF DESCRIPTION OF THE DRAWINGS in section along FIG. 4, is an enlarged elevational view taken in section showing-the latch assembly-hinge combination in Y the door-open position; and

the latch assembly-hinge combination.

DETAILEDDESCRIPTION OF THE DRAWINGS 1 I Shown in FIG. 1 is a fragmentary perspective view of an aircraft cabin 10 in the passenger area where, typically, there are windows 12 in the fuselage, and seats 14 attached to the floor 16. In the ceiling and upper wall area is a baggage storage space 18 enclosed with a front wall 20. A plurality of openings 22 are in the wall for the convenience of the passengers in stowing luggage and small items of convenience. Each opening is covered by a door 24 which is hingedly mounted along its upper edge 26 to the upper edge 28 of the opening. In this manner the door may be raised, as shown, out of the way of the passenger in storing and retrieving personal belongings. It is in the hinge and latch'assembly for holding door 24 in this open position that this invention is used. Of course, it is obvious that this usage is simply one illustrative example and many other examples will become readily apparent after one embodiment of the invention is understood.

FIG. 2 is a sectional view taken along the line 22 of FIG. 1. The door hinge 30 extends along the upper edge 26 of door 24 and the upper edge 28 of the opening in wall 20. This hinge includes an anchor leaf 32, and a swinging leaf 34 pivoted to it by a hinge pin or pintle 36. The anchor leaf 32 is a flat mounting strip which is fastened to the inside surface 38 of the opening upper edge 28 with the pintle 36 parallel to and spaced above the edge. The swinging leaf 34 consists of a strip having an arcuate portion 40 doubling back over a radially straight shoulder portion 42, the end of which is pivotally connected to anchor leaf 32 by pintle 36. Arcuate portion 40 terminates at its other end in a flat door mounting strip 44. Upper edge 26 of door 24 is attached to this strip. Shoulder portion 42 has a width from pintle 36 to its juncture with arcuate portion 40 which is greater. than the distance of pintle 36 from edge 28. This width of shoulder portion 42 is the length of the radius about which arcuate portion 40 is curved, thus permitting it to be rotated under edge 28 when door 24 is opened, i.e., moved to the right in FIG. 2 as shown by arrow 46.

The hinge structure just described preferably is formed of sheet material and may extend continuously across the length of the upper edge 26 of door 24, except for a small cut-out portion for installation of a latch assembly 48 at about its mid-section.

Latch assembly 48 consists of a base 50, arm 52, spring 54, adjustment bolt 56, and a pair of rollers 58 rotatably connected on axle 60 to arm 52. Base 50 is attached to the inside surface 38 of front wall 20 near the upper edge 28 of the opening 22. This base has protruding ears 62 between which arm 52 is pivotally mounted on pivot pin 64. Arm 52 extends downwardly over the arcuate portion 40 and rollers 58 bear against the arcuate surface as the door 24 is moved from closed to open position. Arm 52 has a rear portion 66 extending rearwardly of, or upwardly from, pivot pin 64. A compression spring 54 is positioned between this portion 66 and the base 50 to urge the rollers 58 against the arcuate surface 40. As will be explained hereinaf- 4 ter, an adjustment bolt 56 extending between base 50 and rear portion 66 is adjusted to regulate the precise open position of the door in order that all doors in open position may be in alignment.

FIG. 3 is an enlarged sectional view similar to that of FIG. 2. The door 26 is in its closed position. A section 68 of arcuate portion 40 of the swinging leaf 34 has been cut out to permit its passage down over ears 62 of latch base 50. A section of the radially straight shoulder portion 42 has been removed for the same reason. It is these cut-out sections that make the use of spaced rollers 58 on axle 60 a necessity since a single roller would drop through the cut-out sections when the door 26 is opened and the latch would be inoperative in holding the door open.

Base 50 is fastened to the opening upper edge 28 by means of bolts 70 passing through the base 50 and into nuts 72 imbedded into front wall 20. Base 50 also has a threaded receptacle 74 to receive the threaded end of adjustment bolt 56. Compression spring 54 seats over receptacle 74 on base 50. A spring top 76 fits over the top of the spring and its rounded upper surface 78 bears against the undersurface of rear portion 66 of arm 52. This continually urges rollers 58 against arcuate portion 40 when the door 26 is closed to provide an anti-rattle feature for the latch.

Rear portion 66 of arm 52 has an appropriate opening to permit the upper part of bolt 56 to extend through it. Arm 52 may thus pivot on pivot pin 64, as the door is opened, and there is no interference from bolt 56 until the upper surface 80 of arm rear portion 66 abuts against the head of bolt 56.

In FIG. 4 there is shown the latch assembly when the door 26 is in its open position. Here the door has moved about its pivot point, pintle 36, to a substantially horizontal position. When this occurs the movement of the arcuate portion 40 on the swinging leaf 34 is beyond the length of lever arm 52 and rollers 58 drop down onto the radially straight shouldered portion 42, under the influence of compression spring 54 on the rear portion 66 of arm 52. When this occurs, compression spring 52 moves upper surface 80 of rear portion 66 of arm 52 against the head of bolt 56. This limits the amount of travel of rollers 58 along the shouldered portion 42. Thus, proper adjustment of bolt 56 will determine the proper penetration of rollers 58 along shoulder portion 42. The amount of penetration, or movement of rollers 58 along shoulder 42, determines the angle at which door 26 remains open. It is desirable for all doors to be open when passengers board, and all open doors should be in angular alignment. A simple rotation of adjustment bolt 56 performs this alignment function.

To permit adjustment of the door-open position, and also to permit the door to be closed, there must be an angular relationship between pivot pin 64, the point of contact 82 between rollers 58 and shoulders 42, and hinge pintle 36. This angle must always be less than 90. When roller 58 is moved inwardly on shoulder 42, door 28 moves upwardly, and when roller-58 is moved outwardly on shoulder 42, door 28 moves downwardly. Also, when this angle is less than 90, downward hand pressure on door 26 will cause rollers 58 to move rearwardly (to the left in FIG. 4) and to roll over the semicylindrical surface 40 of swinging leaf 34 as the door closes. In addition to the angle, the hand pressure required to close the door is a function ofthe door length, length of lever arm 52, the position of pivot pin 64 relative to each end of the arm 52, and the compressive force of spring 54. However, these relationships may be determined with a minimum of experimentation and therefore need not be set forth.

In FIG. 5 the hinge and latch assembly is shown in exploded perspective for a better showing of the relationship of the various parts. Looking outwardly from within the baggage compartment, the door hinge 30 is shown with its anchor leaf32 in position for attachment to the upper edge 28 of front wall 20. Door 26 is in position for attachment to door mounting strip 44 of hinge swinging leaf 34. A portion 68 of the semicylindrical surface 40 and shoulder portion 42 has been removed to permit installation of base 50 over anchor leaf 32 on front wall 20. Bolts passing through ape'rtures 84 in base 20 is a typical but not all-inclusive fastening means for this purpose. Compression spring 54 and spring top 70 are in position between threaded receptacle 74 on base 50 and the undersurface of rear portion 66 of arm 52. Top 70 has an aperture 86 to per-. mit insertion of bolt 56 through it. Bolt 56 passes through the axial center of springs 54, the end of which fits over receptacle 74, and the threaded end of bolt 56 threads into the receptacle 74.

Arm 52 fits between ears 62 and'has inturned flanges 88 along its edgesfor reinforcement. Apertures 90 are provided therein for attachment to the ears 62 of base 50. Bars 62 have aligned and cooperating apertures 92.

Pivot pin or bolt 44 is adapted to be passed through apt ertures 90 on arm 52 and apertures 92 in ears 62 to hold arm 52 for pivotal movement. Nut 94 fits over the end of bolt 64.

The lower end 96 of arm 52 also has apertures 98 through which an axle 60 may be passed for rotatably mounting rollers 58. These rollers are mounted on opposite sides of arm 52 so that they might engage the outer surfaces of arcuate portion 40 on opposite sides of the cut-out portion. They also engage opposite sides of the cut-out portion of the radially straight shoulder portion 42 when door 26 is moved to its open position;

While certain exemplary embodiments of this invention have been described above and shown in the accompanying drawings, it is to be understood that such embodiments are merely illustrative of, and not restrictive on, the broad invention and that we do not desire to be limited in our invention to the specific constructions or arrangements shown and described, for various obvious modifications may occur to persons having or dinary skill in the art.

What is claimed is: 1. A latch assembly in combination with: a hinge having an anchor leaf, pintle and swinging leaf, said swinging leaf comprising a radially straight shoulder portion extending from said pintle and terminating in an arcuate portion having its radius substantially the same as the length of said shoulder portion, said arcuate portion terminating in a means to which a door may be mounted, said latch assembly comprising a base, an arm pivotally mounted on said base, said arm having one end engaging the surface of said arcuate portion when said hinge is in closed position and engaging said shoulder portion when said hinge is in open position,

said arm having a rear end opposite said one end and a pivotal connection with said base intermediate said ends, and

a compression spring between said rear end and said base to retain said one end of said arm against said shoulder portion when said hinge is in open position.

2. A latch assembly as set forth in claim 1 wherein said one end of said arm has a pair of spaced rollers thereon in rolling engagement with said surface of said arcuate portion and said shoulder portion.

3. A latch assembly as set forth in claim 1 including an adjustment bolt threadedly inserted in a threaded aperture in said base, the head of said bolt contacting the outer surface of said rear end of said arm to limit the outward movement thereof by said compression spring.

4, A latch assembly as set forth in claim 1 wherein said arcuate portion and said shoulder portion has a portion thereof removed to permit fastening of said base to said anchor leaf.

5 A la'tch assembly as set forth in claim 1 wherein saidbase has spaced upstanding ears with aligned apertu'res therein, said arm has at least one aperture therein,

and a pivot pin through said apertures for pivotally connecting saidarm to said base.

6. A latch assembly as set forth in claim 5 wherein said arm has spaced downturned reinforcing flanges with apertures therein.

7. A latch assembly as set forth in claim 1 wherein the angle between the plane of said shoulderportion and a line passing through the pivot point of said arm and the point of contact of said one end of said arm with said shoulder portion is less than when said hinge is in open position.

8. A latch assembly as set forth in claim 1 and a spring top on said spring, said spring top having a portion fitting into the spring convolutions, an aperture therein, and an arcuate surface contacting the undersurface of said arm rear end. 

1. A latch assembly in combination with: a hinge having an anchor leaf, pintle and swinging leaf, said swinging leaf comprising a radially straight shoulder portion extending from said pintle and terminating in an arcuate portion having its radius substantially the same as the length of said shoulder portion, said arcuate portion terminating in a means to which a door may be mounted, said latch assembly comprising a base, an arm pivotally mounted on said base, said arm having one end engaging the surface of said arcuate portion when said hinge is in closed position and engaging said shoulder portion when said hinge is in open position, said arm having a rear end opposite said one end and a pivotal connection with said base intermediate said ends, and a compression spring between said rear end and said base to retain said one end of said arm against said shoulder portion when said hinge is in open position.
 2. A latch assembly as set forth in claim 1 wherein said one end of said arm has a pair of spaced rollers thereon in rolling engagement with said surface of said arcuate portion and said shoulder portion.
 3. A latch assembly as set forth in claim 1 including an adjustment bolt threadedly inserted in a threaded aperture in said base, the head of said bolt contacting the outer surface of said rear end of said arm to limit the outward movement thereof by said compression spring.
 4. A latch assembly as set forth in claim 1 wherein said arcuate portion and said shoulder portion has a portion thereof removed to permit fastening of said base to said anchor leaf.
 5. A latch assembly as set forth in claim 1 wherein said base has spaced upsTanding ears with aligned apertures therein, said arm has at least one aperture therein, and a pivot pin through said apertures for pivotally connecting said arm to said base.
 6. A latch assembly as set forth in claim 5 wherein said arm has spaced downturned reinforcing flanges with apertures therein.
 7. A latch assembly as set forth in claim 1 wherein the angle between the plane of said shoulder portion and a line passing through the pivot point of said arm and the point of contact of said one end of said arm with said shoulder portion is less than 90* when said hinge is in open position.
 8. A latch assembly as set forth in claim 1 and a spring top on said spring, said spring top having a portion fitting into the spring convolutions, an aperture therein, and an arcuate surface contacting the undersurface of said arm rear end. 